At approximately 21:30 UTC+2, while off the Wild Coast of the Transkei, a muffled explosion was heard and the Oceanos lost her power following a leak in the engine room's sea chest. The ship's engineer reported to Captain Yiannis Avranas that water was entering the hull and flooding the generator room.[2] The generators were shut down because the rising water would have shorted them. The supply of power to auxiliary equipment which ran the engines had been severed, so the ship was left floating adrift.

The water steadily rose, flowing through the 10 cm (3.9 in) hole in the bulkhead and into the waste disposal tank. Without check valves in the holding tank, the water coursed through the main drainage pipes and rose like a tide within the ship, spilling out of every shower, toilet, and waste disposal unit connected to the system.

Realizing the fate of the ship, the crew fled in panic, neglecting to close the lower deck portholes, which is standard policy during emergency procedures. No alarm was raised. Passengers remained ignorant of the events taking place until they themselves witnessed the first signs of flooding in the lower decks. At this stage, eyewitness accounts reveal that many of the crew, including Captain Avranas, were already packed and ready to depart, seemingly unconcerned with the safety of the passengers.